Enhanced resistive switching behavior of CH3NH3PbI3 based resistive random access memory by nickel doping

Abstract

Excessive iodine vacancies (VIs) in the methylammonium lead halide perovskites (MAPbI3) based resistive random access memories (RRAMs) will cause resistive switching (RS) performance degradation. In this study, nickel ions are utilized to limit the excessive VIs in MAPbI3 film. Based on the analysis of X-ray diffraction and X-ray photoelectron spectroscopy, it can be found that the doped nickel ions partially replace lead ions, which can effectively improve lattice integrity and suppress generating of the PbI2 and Pb0 to limit excessive VIs. The RRAM devices based on MAPbI3 and Ni doped MAPbI3 films as the resistive switching layer are fabricated in air atmosphere. Compared with the MAPbI3 device, the Ni doped MAPbI3 device shows more remarkable RS performance. The ON/OFF ratio and endurance of the Ni doped MAPbI3 device has reached 103 and 300 cycles. Moreover, illumination in the forming stage can further improve the ON/OFF ratio and endurance of the Ni doped MAPbI3 device to 104 and 400 cycles. This work provides a new method for the optimization of organic−inorganic hybrid perovskite RRAM with high ON/OFF ratio and stable endurance.